The number of adventitious roots of two- and six-row barleys (Hordeum vulgare L.) grown under irrigation at Bozeman, Montana in 1970 and 1971, was related to yield and other agronomic characteristics. Adventitious roots were counted shortly before heading and at maturity and correlated with 15 agronomic characteristics. Adventitious root number was not correlated with yield of barley, except for two out of six cases in two-row barley. Roots per tiller, per plant and per square metre were all positively correlated with each other. The number of kernels per spike increased as roots per tiller increased but decreased with a high number of tillers per plant. Kernel plumpness and numbers of tillers were negatively correlated in two-row barley, but not in six-row barley. Cultivars differed significantly in yield and adventitious root number. Six-row barley had more roots per tiller but fewer tillers per square metre than two-row barley. Roots per tiller and roots per square metre measurements had the best repeatability between years for six-row barley, but no root measurements were consistent over years for the two-row type. Tillers per plant measurements for both two-row and six-row barleys and tillers per square metre for just two-row barley were consistent over years. Tiller and root number interact and are usually positively related. The genetic variation for root number shown here could be used in crosses for selection of superior genotypes.Key words: Barley, Hordeum vulgare, adventitious roots, subcrown internode, yield components, seeding rate
Evaluation of hybrid populations of (F3) alfalfa as a sourse material for breeding in conditions of high soil asidity